Train control



. H. a. TAYLOR June ll, 1929 TRAIN CONTROL Filed Nov. 17, 1924 CLI Patented June l1, 1929.

UNITED STATES PATENT'OFFICE.

HERBERT B. TAYLOR, OF ROCHESTER, N EW YORK, ASSIGNOR TO GENERAL RAILWAY SIGNAL COMPANY, 0F ROCHESTER, NEW YORK.

TRAIN CONTROL.

Application led November 17, 1924.

posed when the vehicle speed has increased above a safe value under the existing traffic conditions in a given section of the track- Way. It is obvious that if for any reason the driving mechanism for this speed responsive device becomes broken or disconnected, the device will indicate a Zero speed,

and the car-carried equipment Willnot set up'the desired speed restriction;

With the above and other considerations in mind it ifs-proposed in accordance with the present invention to provide means for -checking the operation of the driving mechanism for the car-carried.` speed responsive device, and for initiating an automatic restrictive control if this device fails to operate While-the train is in motion.; and more specifically, it is proposed to provide apparatus for imposing an automatic brake application on the vehicle if the car-carried speed responsive device fails to indicate agiven 'speed after steam has been impressed onthe locomotive cylinders for a. limited period of time.

Other objects, characteristics, and advantageous features of the present invention will become apparent as the description thereof progresses.

In the drawings, Fig. 1 represents the checking device comprising the present invention, together with a diagrammatic representation of the trackway `and car-carried apparatus `of a. simplified automatic train control system of the train speed control type; and

Fig. 2 is a partial view of a modified form of the checking device shown in Fig. 1.

It is understood that Athe checking apparatus for the speed responsive device comprising the present invention might be used in connection With any suitable form of automatic train control system of the speed control type, but Vfor the purpose of illustra- Serial No, 750,309.

tion, an extremely simple form of train speed control system employing the Well known continuous inductive .method of influence communication has been shown. Before describing the check for the drive of the speed responsive device, a brief description of the simplified train control system shown will be given. y

Referring to Fig. 1, the track rails 1 have been shown divided into the usual blocks by the insulating joints 2, the block I and the ends of tWo adjacent blocks H and J having been shown. The usual track relays 3 are connected across the track rails 1 at the entrance ends of the blocks,'fthese relays being energized by the track batteries 4: Which are connected 'across the track rails at the exit ends of the blocks; the normal direction of tratlic being indicated by the arrow. The track relays 3 operate the movable Contact fingers 5 and 6 which control a circuit for impressing an alternating control current across the track rails at the entrance endsA of each block from the transmission line 7 this circuit including the transformers 8 and 9 as clearly shown.

The usual Wayside signals Z of the semaphore type have been shown in av conventional manner at the entrance of each block, it being understood that Lany other suitable type of Wayside signals might be employed, or the system may be used Without Wayside signals. e

It is obvious that, if a train yis located in a given block, its Wheels and axles Will shunt the track batt-ery 4 and the secondaryy Winding of thetransformer 9, causing ther track relay 3 to be cle-energized and the control current to be cut off or substantially reduced in the track vrails behind the train.

The de-energization of the track relay of I each block Will cause the control vcurrent to be cut off from the track rails in the block next in the rear by the retraction `of the conat A, the output circuit of this amplifier being connected to the main relay MR as shown. This relay MR may be a single element alternating current relay, of the vane or rotor type operated split phase, or by using a rectifying tube or tubes, this relay may be a direct current relay of the tractive type. This main relay MR is provided with a movable contact finger 12 and a stationary front contact 13, which contacts are included in a control circuit as hereinafter described.

A speed responsive device is provided for indicating or determining the vehicle speed, and may take any suitable form; Vbut for the purpose of illustrating the invention, a simple centrifuge G has been shown. This centrifuge G comprises a shaft 14 geared or otherwise suitably driven from an axle of the vehicle, and carrying a fixed collar 15 and a movable collar 16, these collars being connected by Athe links 17 carrying the weights 18, and being urged apart by the spring 19. It is evident that'as the vehicle r speed increases, the weights 18 will be thrown outwardly by centrifugal forse drawing the movable collar 16 downwardly against the pressure of the spring '19. A pivotally supported speed arm 20 engages a groove in the movable collar 16, and is arranged to bemoved over the contact segments 21, 22 and 23 and 24 in accordance with the vehicle speed as indicated by the centrifuge G. These contact segments act to make and break various control circuits at different speeds as hereinafter described.

The automatic control of the brakes of thev vehicle may be effected in any suitable man.- ner and by means of any suitable automatic brake control devices. As the automatic initiation of a brake application is usually elected by means of some suitable air valve, an electro-pneumatic valve EPV has been shown in the drawings, it being assumed that this electro-pneumatic valve acts in some suitable manner to initiate a brake applicaY tion upon the de-energiZation of a circuit through its windings.

Referring now more particularly to the apparatus comprising the present invention the means for checking the operation of the speed responsive device includes a combined steam and air operated circuit controlling device D. This device D comprises a steam chamber 25, which is closed at one end by a flexible diaphragm 26,and which is connected by a suitable pipe 27 to the steam header or pipe between the throttle valve and the locomotive cylinders. The diaphragm 2G operates a valve 28 against the pressure of a spring 29, this valve 28 acting to vent the air chamber 30 to atmosphere through the ports 31 and 32 when steam pressure is supplied to the chamber 25, at the same time closing the air supply pipe 33. The air chamber 30 is provided with a flexible diaphragm 34 which is connected to a movable contact member 35 and is biased by the spring 36. The air supply pipe 33 is connected to the main reservoir of the train air brake system or other suitable source; and hence, when no steam pressure is supplied to the chamber and the port 31 is closed by the valve 28, main reservoir pressure will be supplied to the air chamber 30, causing the diaphragm 34 to move to the left against the pressure of the spring 36, thereby bringing the contact member 35 into a position to engage its associated stationary contacts 37 and 38. When the air chamber is vented to atmosphere, the contact member will be moved by the spring 36 to disengage the fingers 37 and 38.

In the modification of the invention shown in Fig. 2, the air supplying pipe 33 is pro'- vided with a check valve 44, the remainder of the apparatus being identical with that shown in Fig. 1. The cheek valve may be of any suitable type, and is shownin a simv plified form, the operation of which will be readily apparent from the drawings. In this form of the invention, the pipe 45 leading through the check valve 44 to the air pipe 33,

is connected to the brake cylinder pipeof the well known ET equipment, or other suitable connections are made so that air'pressure is admitted to the pipe 45 only when the brakes are being applied on the engine and tender. The check valve 44 is arranged to admit air pressure to the pipe 33 when these brakes are applied, and to Yprevent the air thus admitted from being exhausted through the pipe 45 when the brakes are released.

Operatz'oa.-All of the apparatus in the drawings has been shown in its normal operating condition, that is, the positions of the various devices are such as would be assumed with a train running at a speed below'the Y maximum but above the minimum permissive limit, under clear traffic conditions ahead, and with the locomotive throttle valve open. The letters B and C have been used to indicate the opposite poles of a suitable source of energy, preferably a storage battery.

Referring briefiy to the operation of' the simplified train control system shown, assuming a train to be proceeding under clear trafc conditions, that is, with no other train in the block in which it is located or in the next block in advance, train control current flows in the track rails and induces currents in the receiving coils 11; and these currents are amplified by the amplifier A and cause energization of the main relay MR, 'attract ing its contact finger 12 and closing its front Contact 13. An energizing circuit for the electro-pneumatic valve EPV is now completed, which circuit may be traced as follows :-from the battery terminal B, contact nger 12 andthe front contact 13 of' the main relay MR, wire 39, contact segment 23, speed arm to contact segment 24, and wires 40 and 41 through the winding of the electropneumatic valve EPV to the battery terminal C. lith the electro-pneumatic valve EPV energized, the train may proceed in the clear territory under the sole restriction indicated below.

The Contact segment 23 is preferably constructed to impose a maximum speed limit under clear traffic conditions, that is, when the train speed exceeds a given maximum speed, say 60 miles per hour, t-lie .speed arm 20 will disengage the contact segment 23 and the energizing circuit for the electro-pneumatic valve traced above, will be broken, causing a de-energization of this valve and a consequent automatic brake application which continues until the train speed has been brought below the maximum limit, when the.

speed arm 20 again engages thesegment 23 and the energizing circuit for the electropneumatie valve is again completed.

lVhen a train equipped with the system shown eiiteis a block in which caution or danger traffic conditions exist, that is, a block in which another train is located or the lirst block in the rear of such occupied block, the train control current is cut off from the track rails and the receiving coils 11 do not have current induced therein, which condition re suits in the de-energization of the main relay MR and the consequent retraction of its contact finger 12. When the contacts 12 and 13 of the main relay MR are open, the energizing circuit for the electro-pneumatic valve EPV traced above is broken, and an automatic brake application results. This automatic brake application continues until the train speed has been reduced to a'minimum value, assumed to be 15 miles per hour, at which speed the arm 20 engages the contact segment 22, completing an energizing circuit for the electro-pneumatic valve which may be traced as follows z-from the battery terminal B, through contact segment 22 and speed arm 20, contact segment 24,l wires 40 and 41 and the winding of the electro-pneumatic valve EPV to the battery terminal C. The train may now proceed in the caution or danger territory at a speed below the minimum limit, and is held to that speed until trailic conditions ahead become more favorable.

Referring now more particularly to the segment is arranged to disengage the arm when zero speed is indicated. As the throttle valve is open, the circuit controlling device is in the condition shown, that is, the steam chamber 25 is supplied with pressure, actuating the valve 28 and so venting the air chamber 30 to atmosphere and causing the movable Contact to disengage its associated stationary contacts 37 and 38. The energizing circuit for the electro-pneumatic valve EPV will be broken when the speed arm 20 disengages the contact segment 24, causing an automatic brake application and bringing the train to a stop. The engineer now may repair the driving mechanism or, preferably, render the automatic brake control apparatus inactive by the operation of a suitable cut-out device, not shown, which is provided iii connection with the automatic train control system, this cut-out device being protected against unauthorized operation to avoid an automatic brake application by means of a sealed casing or other suitable means.

1f the steam is cut off at the time at which the drive mechanism becomes disengaged, the

valve 28 of the circuit controlling device D` will close the port 31 and open thepipe 33 which is connected to the main reservoir air pressure, causing the diaphragm 34 to be moved to the right and thus causing the contact member 35 to engageits associated contacts 37 and 38. A circuit to the electropneumatic valve EPV will now be completed which circuit `may be traced as follows:- from the battery terminal B,.contact segment 22 through the speed arm 20 to the contact segment 21 which engages the arm 2O at speeds below 3 miles per hour, wire 42, contact linger 37, contact member 35 and contact finger 38 of the circuit controlling device D, Wires 43 and 41, and the winding of i the electro-pneumatic valve EPV to the battery terminal C. With the electro-pneumatic valve energized, the train may proceed without restriction so long as the throttle is closed, and no steam pressure is applied to the chamber 25, but as soon as the throttle is opened the contacts 35, 37 and 38 will be opened in the manner described above, and the electro-pneumatic valve will be deenergized, causing an automatic brake application and bringing the train to a stop.

y The spring 29 of the circuit controlling device'D operates tol move the valve 28 into a position to open the air pipe 33 and to close the port 31 when no steam pressure is present in the chamber 25. This spring 29 also serves another function, namely, to prevent a slight steam pressure arising from a leaking throttle valve from moving the valve 28 when the train is not in motion.

It should be noted that if the train is proceeding under caution or danger traiiic conditions at the time at which the drive mechaiio nism becomes disengaged or inoperative, the operation of the device D and its associated circuits is the same as that described in connection with a failure of the drive under clear traiic conditions, the circuit to the electropneumatic valve EPV through the contacts 37,35, and 38 of the device D being completed through the contact segment 22 which is connected to the battery terminal B, the arm 20, and the segment 21.

Now assume that the train under consideration comes to a stop under either clear, caution or danger' traiiic conditions. As the train approaches a zero speed, the throttle will be closed and hence the contacts 37 and 38 are closed by the contact member in the manner described above, thus completing a circuit to the electro-pneumatic valve EPV through the contact segments 22 and 2l, which circuit has been traced above. Vhen the train starts, the throttle is, of course, opened, closing the pipe 33 and venting the air chamber 30 to atmosphere through the ports 31 and 32. The volume of the chamber 30 and the size of the ports 31 andV 32 are so constructed and arranged that a certain time will elapse before the spring 36 moves the contact member 35 .out of engagement with its associated contacts 37 and 38, this time being long enough to allow the train to get in motion and so to bring the speed arm 20 into engagement with the contact segment 24, thereby completing a circuit to the electro-pneumatic valve EPV through the Contact segment 22, which circuit has been traced above.

It is evident from the discussion given above that when the centrifuge G is in its zero speed position due to a lack of motion of the train, an automatic brake application will not result.

If a train equipped with the apparatus shown in Fig. l is proceeding at a high rate of speed and with the throttle valve closed, and if the drive mechanism becomes disengaged `under these conditions, it is obvious th at the train might proceed into a caution or a danger block without restriction particularly if it is traveling on a down grade. In the modification shown in Fig. 2, this possible danger is avoided byV supplying the air pressure for the pipe 33 from the brake cylinder pipe of the well known E. T. equipment through a check valve as described above. With this arrangee ment, pressure will not be supplied to the air chamber 30 unless the brakes are being applied on the locomotive, and hence the contacts 37, 35 and 38 cannot be closed to energize the electro-pneumatic valve EPV unless a brake application is being made.

In a system embodying the modification shown in Fig. 2, when an automatic brake application occurs as a result of'a failure of the governor drive shaft, air pressure is suplied from the brake cylinder pipe through the pipe 45, the check valve 44 and the pipe 33 to the chamber 30, and, if the throttle is still closed, the chamber 30 is charged and the contacts 37 35 and 38 are closed. This causes the energization of the electro-pneumatic valve EPV and permits release of. the brakes as described above, and when the brakes are released, the air pressure in the chamber 30 is trapped by the check valve 44, thus maintaining the contacts 37 35 and 38 closed. After a time, the pressure trapped in the chamber 30 leaks away through the valves 44 and 28, the contacts 37, 35 and 38 are opened by the spring 36 and a second brake application results. In this manner, the progress of the train is successively restricted when the steam is cut off and the governor driving mechanism is disconnected, so that a train may not proceed without restriction under these conditions. If it is found desirable to decrease the time interval during Which the electro-pneumatic valve EPV is main# tainedy energized, the valve 28 may be provided with suitable leak ports which will permit the air pressure which is trapped in the chamber 30 by the check valve 44, to leak away more rapidly, thus causing more frequent successive brake applications.

Considering now a train equipped with a control system embodying the modification shown in Fig. 2, assume that such train comes to a stop under clear, caution or dangertraffic conditions, and with the governor driving mechanism in its proper operating condition. As the train approaches a stop, the steam will be cut oftl and the brakes, including the brakes on the engine an d tender, will be applied, thus causing the valve 28 of the device D to be moved to the right, admitting air pressure from the brake cylinder pipe to the chamber 30, and so closing the contacts 37 35 and 38. An automaticbrake application as a result of the zero speed condition of the centrifuge G will thus be avoided by the energization of the electro-pneumatic valve EPV through the contacts 37, 35 and 38, and acircuit which has been traced above. If the engine and tender brakes remain applied until the train is about to start, the air pressure in the chamber 30 willbe maintained, and when the brakes are released to start the train, the check valve 44 will trap this air pressure until the train .is in motion and the speed arm 2OV is in engagement With the contact segment 24, thus maintaining the electro-pneumatic valve EPV energized and avoiding an automatic brake application. If, however, the engine and tender brakes have been released while the train is at a stop and the train remains stationary for some time, the air pressure trapped in the chamber 30 may be reduced by leakage to such an extent that the contacts 37, 35 and 38 are opened, the electro-pneumatic valve EPV cle-energized and an automatic brake application is eiected. As a result of this automatic brake application, the

llO

-air chamber 30 is recharged from the brake of the air chamber 30 may be designed to retain this chamber charged and the contacts 37, 35 and 38 `closed for a period of time long enough to permit the train nary stop.

From the description of the device emto make an ordibodying the present invention itis seen that a system has been provided Whereby anautomatic brake application is imposed if the driving mechanism `for the car-carried equip- Y ment becomes inoperative While the train is in motion regardless of traiiic conditions ahead, and further, that this system Will not cause an automatic brake application if the centrifuge or other speed responsive devicehas come to its zero speed position because of lack of motion of the train.

As the governor drive checking device comprising the. present invention has been described in a rather specic manner and in connection With one specific type of train control system, it should be clearly understood that this device may be modified or combined with other equipment, and furtherthat this device could be employed With any suitable type of speed control system Without departing from the spirit of thepresent invention as defined by the appended claims.

What it is desired to secure by Letters Patent is 1.,In an automatic train control system, in combination With a steam propelled vehicle vehicle carried apparatus comprising a speed responsive device driven in accordance With the movement of the vehicle, a brake control device controlled `by said speed responsive device in accordance `With inliuences corresponding to trail-ic conditions ahead, and means for causing an automatic brake application` if saidspeed responsive device indicates a zero speed for more than a limited period of time While steam is supplied `to ,propel the vehicle.

2. In an automatic train control system, in

combinationwvith a steam propelled vehicle,

vehicle carried bra-ke control apparatus including a speed -responsive device driven in accordance With the progress of the vehicle, a control means cooperating with said speed responsive device for applying the brakes of the vehicle yin response to influences corresponding to unfavorable traflic conditions ahead, means for applying the brakes of the vehicle when said speed responsive device registers a zero speed,`and means lfor preventing .saidlast mentioned brake application when no steam is supplied to propel the vehicle and for a limited time interval 'after steam is so app1ed. Y

3. In an automatic train control system, in combination with a vehicle having a steam boiler and a steam engine, vehicle carried control apparatus.l comprising a speed responsive device driven in accordance-With the motion ofthe vehicle, a brake applying'device controlled vby said speed responsive device in accordance Witli influences inductively received'fromthe trackWay and corresponding With traffic conditions ahead, and additional means for actuating said brake applying device if said speed responsive device fails to indicate a motion of the vehicle While Vsteam is beingv supplied to said engine from said steam boiler. l

4. In an automatic train control system, a brake applying Adevice adapted `to apply the vbrakes of a vehicle when ,de-energized,

means for controlling saidbrake applying device including acontrol device operated in accordance Wit-h inliuences corresponding to tratlic conditions ahead anda speed responsive device driven in accordance with the motion of the vehicle, means for de-energizing said brake applying deviceA when said speed responsive device indicates a zero speed and means kfor preventing the de-,energization of said brake applying device while steam is cut ofi' from the propelling mechanism of the vehicle and for a limited interval of time after st eam is admitted to said propelling mechamsm.

5. In an automatic train control system, a brake applying device adapted to apply the brakes of a vehicle when de-energized, means Y for controlling the energization of said brake applying device in accordance Withinfluences corresponding to traffic `conditions ahead and in accordance With the vehicle speed, said means including a speed responsive device driven in accordance With the motion of the vehicle and adapted to de-energize the brake applying device When in its zero speed position, and a switch for maintaining said brake applying device energized as long as steam is not applied to the vehicle propelling mechanism and 'for Va limited time interval after steam has been so applied, said svvitch being operated by fluid pressure. i

y 6. In an automatic train control system, a steam propelled Vehicle, vehicle carried ,brake .control apparatus including means driven in' accordance with the motion of the vehicle and acting to control the vehicle brakes, said brake control apparatus acting to apply the 4brakes of t-he vehicle when said driven Vmeans qperat-ed automatically/after an interval of'- Vnormally energized electro-pneumatic valve acting automatically upon de-energiZat-ion thereof to cause a brake application, a normally closed energizing circuit for said valve including two branches in multiple, a speed responsive device controlling one multiple branch to open it when said device is not rota'ting, and other contacts in the other multiple branch initially opened after an mterval'of delay when steam is supplied to propel the vehicle and maintained open so long as steam is supplied.V Y

9. In an automatic l,train control systeml for steam propelled vehicles, means for determinating, by restricting the vehicle, when the vehicle is in motion including, a circuit controller, and pressure responsive means for operating said circuit controller to open vits circuit when steam is supplied to propel the vehicle and thus restrict Vthe vehicle a short time after said steam is supplied, if the Vehicle, at such time, be motionless.

10. In an Varrangement of the character described for detecting failure of devices driven from car Wheels, means for determining when the car is in motion including, a circuit, and means set into operation upon application of power to propel the car for opening said circuit i the device driven from the car wheels is not operating after an interval of delay.

11. In an automatic train control system,

the combination with aspeed-responsive dedevice driven from the wheels o'f the vehicle, a control device arranged to become effective only after a predetermined lapse of time after vehicle propulsion power has been turned on, and means for automatically applying the brakes of the vehicle when said control device is effective and said speed-responsive device is not rotatinff.

12. In an automatic train control system,A car-carried apparatus comprising a normally energized electro-pneumatic valve, acting automatically upon de-energization thereof to cause a brake application, an energizing circuit for said valve including two branches in multiple, a speed responsive device driven from the car wheels and operating contacts in one of said multiple circuits, said contact-s being openediwhen said speed responsive device is not in motion, and means maintaining cont-acts in said other multiple circuits closed when the vehicle brakes are applied, and for a predetermined time interval after said brakes are released. f f

13. In an automatic train control system,

vehicle carriedapparatus comprising a speed responsive device `driven from the wheels of the vehicle, a brake control device, controlled by said speed responsive device in accordance with influences corresponding to traiiic conditions ahead, means for actuating said brake control device when said speed responsive device is not in motion, and means for preventing such brake application if a brake appli-VV cation is already in'eii'ect, and for a predetermined timeinterval after the release of said brake application.

14:. In an automatic train control system, a speed responsive device driven in accordance with the progress of avehicle, a control device operating after a predetermined interval of delay after the release of the vehicle brakes, and means for automatically applying the vehicle brakes if said contro-l device is operated and said speed responsive device indicates a zero speed; Y

15. In an automatic train control system, an automatic brake applying means, a rotary speed responsive device driven from the wheels of the vehicle, means operated by said speed responsive device for causing an automatic brake application when said speed responsive device is not rotating, a vcontrol device effective whenv the vehicle brakes are applied and for an interval after said brakes are released, said control device acting when effective to prevent said automatic brake application.

16. In an automatictrain control system, a device driven from the car wheels and means for detecting a failure in the driving mechanism of said device comprising a normally closed circuit opening when saidv device is not in operation, a second circuit, contacts for controllingsaid second circuit when said device is notin operation and means for closing said contacts comprising a cylinder containinga flexible diaphragm connected to said contacts, and means for admitting air pressure to saidcylinder to close said contacts when the power for propelling thevehicle is cut o and for a predetermined time interval after such power is applied.

17. In an automatic train control system, a device driven from the c ar wheels land lmeans for detecting a failure in the driving mechanism of said device comprising a normally closed circuit opening when said device is not in operation, a second circuit, contacts for controlling said second circuit when said device is not in operation and means `for closing said contacts comprising a cylinder containing a flexible diaphragm connected to said contacts, and means for admitting air pressure to said cylinder to close said contacts when the power for propelling the vehicle is cut oi and the vehicle brakes are ap plied, said means acting to maintain said air pressure to maintain said contacts closed for a predetermined time interval after the power is applied and after the brakes are released 18. In an automatic train control system, a device driven from the car Wheels and means for detecting' a failure in the driving mechanism of said device comprising a brake applying device, means for operating said brake applying device when said driven device is not in operation and means for preventing such operation of said brake applying device unless power is being applied to propel the vehicle.

19. In an automat-ic train control system, in combination with a steam propelled vehicle7 vehicle carried brake control apparatus including a speed responsive device driven in accordance With the progress of the vehicle, a control means cooperating With said speed responsive device for applying the brakes of the vehicle in response torinluences corresponding to unfavorable traffic conditions ahead, means for applying the brakes of the vehicle when said speed responsive device registers a zero speed, and

retarded action fluid pressure operated means for preventing said last mentioned brake application when no steam is supplied to propel the Vehicle. e

20. In an automatic train control system, a brake applying device for applying the brakes of a vehicle, means for controlling said bra-ke applying device including a control device operated in accordance With the influences corresponding/to trac conditions ahead and a speed responsive device driven in accordance With the motion of the vehicle, means for causing said brake applying device to apply the brakes When said speed responsive device indicates Zero speed, and means for preventing such application of said brakes during the time that steam is cut oil from the propelling mechanism of the vehicle and for a limited interval of time if steam is admitted to said propelling mechanism.

In testimony whereof I afX mysignature.

HERBERT B. TAYLOR. 

